Users are increasingly using networks such as the Internet to access content, such as video files and live streaming/video on demand content, via client machines. Such content is often large, time sensitive, or both. As demand for such content increases, there are challenges in distributing that content efficiently and with high quality.
Two ways that content owners can distribute content are by using their own servers or buying the service of a content delivery network (CDN). In the later case, content owners typically contract with CDNs to provide content to clients, e.g., in exchange for a fee. Requests by clients for content are directed to CDN nodes that are close by, e.g., the fewest hops away from the clients. The client then downloads the content from the appropriate CDN node. In both cases, content is distributed by servers, owned by either the content owner directly or the CDN. Unfortunately, as demand on server capacity increases (e.g., as the content size gets bigger and/or the number of requests to the content increase), meeting that demand by increasing capacity is often very expensive, requiring a larger number of servers or more powerful servers to be deployed.
Another way that content can be distributed is through use of peer-to-peer (P2P) systems. In a typical P2P scenario, a node downloads content from the system, and also uploads content to other nodes. In a hybrid content distribution system, a fraction of the content is transmitted by the servers and the rest is transmitted by nodes using their uplink capacity. Unfortunately, ISPs are facing increased network congestion from P2P and hybrid content distributions. One reason is that traditional P2P approaches rely on peers making independent routing decisions based on local information. This is approach is typically taken so that there is no single scalability bottleneck and no single point of failure. Unfortunately, such an approach may result in poor performance, inefficient resource utilization, and other shortcomings.
Therefore, it would be desirable to have a better way to distribute information over a network.